CN1074322A - Contrast electronic beam current restraint device with secondary brightness beam restraint device - Google Patents
Contrast electronic beam current restraint device with secondary brightness beam restraint device Download PDFInfo
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- CN1074322A CN1074322A CN92114696A CN92114696A CN1074322A CN 1074322 A CN1074322 A CN 1074322A CN 92114696 A CN92114696 A CN 92114696A CN 92114696 A CN92114696 A CN 92114696A CN 1074322 A CN1074322 A CN 1074322A
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- brightness
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N3/00—Scanning details of television systems; Combination thereof with generation of supply voltages
- H04N3/10—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical
- H04N3/16—Scanning details of television systems; Combination thereof with generation of supply voltages by means not exclusively optical-mechanical by deflecting electron beam in cathode-ray tube, e.g. scanning corrections
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
- H04N5/00—Details of television systems
- H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
- H04N5/57—Control of contrast or brightness
- H04N5/59—Control of contrast or brightness in dependence upon beam current of cathode ray tube
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Abstract
A kind of television system comprises the picture tube beam restriction means, when electronic beam current surpasses first threshold, can reduce the contrast of image and do not influence the brightness of image, if user's brilliance control level surpasses nominal brilliance control level, image brightness reduces, electronic beam current surpassed it and was equal to or greater than second threshold value of first threshold this moment, in the time of in image brightness equals nominal image brightness till, image brightness just reduces.Further to the restriction of electronic beam current, for example relating to the irregular working situation of television system, is to reduce and finish with other brightness.
Description
The electronic beam current restraint device of the present invention about can in television receiver or monitor, using.
Great majority also comprise picture tube beam restriction (BCL-beam current limiting) device and also are called autoelectrinic bundle restriction (ABL-automatic baem limiting) device sometimes such as comprising the television system of picture tube as the television receiver and the monitor of display unit.The effect of BLC device is to prevent that electronic beam current is excessive, and electronic beam current is excessive may to cause luminous point to defocus or " brightness looses ", may damage picture tube under extreme case.Typically, " resupplying " electric current that the BCL device is drawn from the supply of picture tube high voltage power supply by the sense side is felt the average electronic beam current that side is drawn by picture tube, and forms the BCL control signal of expression electronic beam current size.This BCL control signal with feedback system be coupled to the contrast part of television system and brightness part one of or two, reduce electronic beam current during above set threshold value with the electronic beam current of box lunch sense side.Contrast is partly controlled the gain that is coupled to the picture tube video channel, thereby control is coupled to the vision signal peak-to-peak amplitude of picture tube.The black level of the vision signal that is coupled to picture tube is partly controlled in brightness.
Most of BCL devices are the brightness that reduces to show again image before reducing its brightness in the sequence mode earlier, because the change of contrast and brightness change relatively the subjective less attention that is subjected to spectators.Yet the luminance fluctuationization that can note can produce in other good image of forming.The brightness of this BCL induction changes is using the high-gain video channel so that remarkable especially in the television system of screen or optical projection system etc. greatly of increase the average image brightness output.
One aspect of the present invention promptly under normal function situation, does not wish to make the BCL device to reduce to show the brightness of image about such cognition again.Yet, another aspect of the present invention is about such cognition, though promptly may be only with reduce intensity level or reach the restriction of electronic beam current near the showing the contrast of image again of nominal value (middle scope), yet this single contrast electronic beam current restriction is to having that the image bigger than nominal intensity level is difficult to accept and being invalid.Therefore, if user's brightness settings greater than corresponding nominal intensity level and when only using the restriction of contrast electronic beam current, picture contrast can be decreased to minimum level and need not to reduce the acceptable level of electronic beam current to.
Another aspect of the present invention is about a kind of BCL device, wherein, if user's brightness settings or during near nominal level, then utilize FR contrast to reduce substantially and need not to reduce brightness.Yet, if user's brightness settings is uncommon when high, BCL device sensing user's brightness settings level and reduce brightness settings to the scope of nominal level.Any additional electronic beam current reduces all to reduce and finish with contrast.
These and other aspects of the present invention describe with reference to the accompanying drawings.
In the accompanying drawing:
Fig. 1 illustrates part, and part is with the television system of line map form with block diagram form, and it comprises the electronic beam current device that constitutes according to one aspect of the present invention; And
Fig. 2-5 shows the characteristic that helps to understand the work of BCL device among Fig. 1.
Fig. 6 illustrates a part with block diagram form, the part modification with Fig. 1 television system of line map form.
The element of illustrative, voltage and current value all indicate in Fig. 1-6.Except that other had indication, resistor values was ohm.The letter " K " expression kilohm, letter ' M ' is then shown megohm.Capacitor value is a microfarad.Magnitude of voltage is a volt (V), and current value then is a micromicroampere.
Television system among Fig. 1 comprises video signal processing unit 1, handles the brightness and the chromatic component of synthetic video input signal, is suitable for driving red, green and blue (R, G and B) output signal of picture tube 3 with generation.Video signal processing unit 1 comprises contrast part 5 and is coupled to R, the G of picture tube 3, the peak-to-peak amplitude of B signal in order to control, and brightness part 7, in order to the black level of control R, G, B signal.Contrast part 5 can be included in such as in the luminance signal treatment channel (not shown) that is incorporated into the TA of Toshiba 8680 processing television signals integrated circuits with brightness part 7.Another program is handled in each red, green, blue vision signal treatment channel of collection or circuit can be contained in such as TA 7730 vision signals that are incorporated into Toshiba with the brightness part corresponding to the contrast part 5 and the contrast part of brightness part 7.High voltage source supply 9 provides high working voltage in response to the horizontal deflection signal that the deflector (not shown) is produced for picture tube 9.The remainder of television system comprises that contrast and brilliance control divide and according to electronic beam current restriction (BCL) device of structure of the present invention among Fig. 1.
The each several part of television system is comprised by the foundation program stored or the control unit 11 that responds the microprocessor that user for example works with the start command signal of remote control unit (not shown) input is controlled.
Control unit 11 for example produces two pulse signals that advance rate multiplier (BRM-binary rate multipli-er) form coding, and is preferred with expression user's contrast.Contrast BRM pulse signal control-electronic switch SWC, this switch comprises part digital to analog converter 13, is coupled to user's response simulation contrast control voltage of contrast part 5 with formation.The contrast that shows image again is directly relevant with the size of user's response simulation contrast control voltage.So the increase of simulation contrast control voltage swing causes the increase of picture contrast, the reduction of simulation contrast control voltage swing then causes the reduction of picture contrast.
Switch SW C and resistor R C1 and RC2 are connected to positive supply voltage (+12V) source.When opening and closing when switch SW C response contrast BRM signal, the level deviation kenel of contrast BRM pulse signal forms at the Rendezvous Point of resistor R C1 and RC2.This level deviation pulse signal is coupled to filtering capacitor CC through low values of resistors RC3, at this, forms user's response simulation contrast control voltage through low-pass filtering.
Control unit 11 also produces the preferred BRM coded pulse signal of expression user's brightness.The control of this brightness BRM pulse signal comprises the electronic switch SWB of a part of digital to analog converter (DAC) 15, is coupled to user's response simulation brilliance control voltage of brightness part 7 with formation.The brightness that shows image again is directly relevant with the size of user's response simulation brilliance control voltage.So the increase of analoging brightness control voltage swing causes the increase of image brightness, the reduction of analoging brightness control voltage swing then causes the reduction of image brightness.
Switch SW B and resistance R B1 are connected to positive supply voltage (+12V) source.When switch SW B opened or closed with response brightness BRM signal, the level deviation kenel of brightness BRM pulse signal formed at the Rendezvous Point of resistor R B1 and switch SW B.To form user's response simulation brilliance control voltage, this low pass filter comprises be connected in series resistor R B2, RB3 and capacitor CB to this level deviation pulse signal by a low pass filter filtering.This low pass filter also comprises and is connected in series in positive supply voltage (+12V) voltage divider between source and the ground, that be made up of resistor R B4 and RB5.Be formed at the Rendezvous Point of resistor R B4 and RB5 corresponding to the voltage of nominal intensity level, and be coupled to the Rendezvous Point of resistor R B3 and capacitor CB.
The BCL device comprises the circuit 17 of the electronic beam current that sensing drawn by picture tube 3, with sensing by high voltage source supply 9 through resistor R S from positive supply voltage (+24V) the source electric current (IS) of drawing and response R, G, B signal.Current IS is commonly referred to as supply of current again and is drawn in horizontal flyback interim by high pressure supply 9 because of it, to replenish (heavily supply) again at the electric current of being drawn on it by camera tube 3 during the horizontal scanning interval.The voltage that resistor R S go up to form being in proportion and being filtered by filtering container CS with supply of current IS's again.Therefore the voltage on the capacitor RS is proportional with the mean value that weighs supply of current IS again, therefore proportional with the mean value of the electronic beam current of being drawn by picture tube 3 usually.
Diode CRQ is generally forward bias, therefore, with its anode through resistor R Q and positive supply voltage (+12V) source is connected and conducting.When diode CRQ conducting, it is filtering capacitor CP ground connection, the voltage filter that capacitor CP is formed resistor R S as previously mentioned.Yet diode CRQ is a reverse bias, so the moment surge of supply of current is again presented non-conduction property.When diode CRQ presents non-conduction property, filtering capacitor CS promptly with the ground decoupling zero with the voltage response that allows resistor R S to go up the to form instantaneous surge of supply of current again.This " disconnecting fast " configuration is a United States Patent (USP) 4,167,025 theme, and name is called " peak value electronics beam clipper (Automatic Peak Current Limiter) automatically ", and in 1979,9,4 are presented to applicant D.H.Willis.
The electronic beam current that resistor R S go up to form represents that voltage is coupled to the threshold value comparator 19 of the NPN transistor Q2 that comprises common base stage configuration through the PNP transistor Q1 of emitter follower configuration.Threshold values comparator 19 also comprises the resistance R G between the emitter that is connected in transistor Q1 and Q2 and determines the voltage divider 21 of reference voltage (VRFF), and this voltage divider comprises resistor R RF1, RRF2 and filtering capacitor CRF.Reference voltage VRFF is coupled to the base stage of transistor Q2.Be connected in the base stage of transistor Q1 and positive supply voltage (+12V) the clamping diode CRC between the source prevents that the voltage that forms in base stage from surpassing one and being a bit larger tham the level (0.7V) of supplying voltage so that prevent transistor Q1 and/or transistor Q2 by regurgitation to voltage breakdown.The collector electrode of transistor Q2 is coupled to positive supply voltage (+24V) source through resistor R B.The BCL control voltage of expression electronic beam current size is formed at the collector electrode of transistor Q2.
The BCL control voltage that is formed at transistor Q2 collector electrode is coupled to the output of contrast DAC 13 through diode CRD.In addition, BCL control voltage is coupled to the PNP transistor Q3 of the emitter follower configuration relevant with brightness DAC 15.Diode CRD isolates contrast DAG 13 and brightness DAC 15.The collector electrode of the transistor Q3 buffer transistor Q2 of emitter follower configuration is so that it is irrelevant to comprise the impedance of the gain of comparator 19 of transistor Q2 and brightness DAC 15.The gain of comparator 19 is determined by the impedance of 13 couples of transistor Q2 of contrast DAC collector electrode and the value that is connected in the resistor R G between transistor Q1 and Q2.Transistor Q3 together with resistor R B2, RB3, RB4 and RB5 also as a comparator, so that user's brightness settings and BCL control voltage is compared.This has relatively determined brightness BCL to be limited to when to begin, and more particularly, guarantees that brightness BCL only can begin to take place usually when user's brightness settings surpasses nominal value (middle scope) brilliance control level
At work, when the electron beam flow of being drawn by picture tube 3 is extremely low, then the base voltage of transistor Q1 by logical diode CRC by clamp to+12.7 volts approximately.When the electron beam flow was high slightly, diode CRC presented non-conduction property and changes with the base voltage that allows transistor Q1.Resistor R S(supply of current IS more promptly flows through this resistor) formed voltage swing is directly relevant with the amount of electronic beam current.Therefore, the size of the voltage that forms in transistor Q1 base stage is oppositely relevant with electronic beam current, so when electronic beam current continued increase, the voltage of the reverse base stage of being correlated with of transistor Q1 then reduced.The emitter voltage of transistor Q1 is followed the base voltage of transistor Q1.Yet back one voltage is not coupled to the collector electrode of transistor Q2, so the electronic beam current restriction does not take place till when transistor Q2 presents conducting.When the emitter voltage of transistor Q2 reaches when being lower than (0.7V) voltage slightly than reference voltage VREF, transistor Q2 presents conducting.The threshold value that the electronic beam current restriction begins to work is quantitatively set up by reference voltage VREF value and resistor R S.
In case the electronic beam current threshold limit is reached, just reduce in the size of transistor Q2 collection by the BCL control voltage that forms on extremely.This contrast control voltage that causes immediately being coupled to contrast part 5 reduces.Yet the brilliance control voltage that is coupled to brightness part does not reduce till when comparator transistor Q3 presents conducting.When following two conditions satisfied, transistor Q3 presented conducting:
1. at resistor BR1 and switch SW B(node 1) essential surpassing of mean value of the pulse signal that forms of Rendezvous Point at resistance R B4 and RB5(node 2) go up the voltage of formation; And
2. must be brought down below at resistor R B2 and RB3(node 3 at the BCL control voltage that transistor Q2 collector electrode forms) macerate a little on formation or voltage.
If, as previously mentioned, the value of resistor R B4 and RB5 through selecting so that when its Rendezvous Point (node 2) is gone up the voltage that forms corresponding to the control level of nominal brightness, then above-mentioned first condition guarantees that brightness electronic beam current restriction does not take place, unless when user's brilliance control is set greater than nominal brilliance control level.
The brightness comparator that comprises transistor Q3 and resistor R B2, RB3, RB4 and RB5 is configured to following manner work.When the mean value of the pulse signal on node 1 is equal to voltage on the node 2, then there is not electric current to flow between the node 1 and 2 in any direction.As a result, the voltage of node 3 equals the voltage of node 1, that is, and and nominal brilliance control level.When the mean value of the pulse signal of node 1 during less than the voltage of node 2, then the voltage of node 3 is less than nominal brilliance control level.When the mean value of the pulse signal of node 1 during greater than the voltage of node 2, then the voltage of node 3 is greater than nominal brilliance control level.As a result, be higher than nominal brilliance control level, otherwise the restriction of brightness electronic beam current does not take place unless the user has set the brilliance control level.
In case during transistor Q3 conducting, brilliance control voltage descends at once with the decline of the BCL control voltage of response transistor Q2 collector electrode.During this period, the Thevenin(Dai Weining of the voltage divider formed by transistor Q3 emitter voltage (BCL control voltage falls less than the base-emitter voltage of transistor Q3), resistor R B3 and by resistance R B4 and RB5 of brilliance control voltage) equivalent electric circuit (voltage, the source resistance value that the voltage of voltage source supplies equals node 2 equals the combination in parallel of resistor R B4 and RB5) determines.Transistor Q2 is saturated when higher electronic beam current at last.After this, the BCL of transistor Q2 collector electrode control voltage will be clamped to the reference voltage VREF that is coupled to transistor Q2 base stage, and this voltage is less than the voltage drop of base stage one collector electrode.As a result, contrast control voltage will be clamped to and be about reference voltage VREF, please note that the voltage drop of diode CRD approximates the voltage drop of transistor Q2 base stage one emitter greatly.Brilliance control voltage will be by clamp extremely by reference voltage VREF, resistor R B3 with as the above-mentioned voltage that thevenin equivalent circuit determined that comprises resistor R B4 and RB5 voltage divider.
Fig. 2-5 illustrates the open loop contrast of BCL device among Fig. 1 and brilliance control characteristic with the variation of electronic beam current, these characteristics value corresponding to each resistor among Fig. 1 (except resistor R B2 and the RB3), is suitable for controlling the above-mentioned TA7730 of Toshiba vision signal and handles contrast and the brightness part of amassing into chip.In Fig. 2-5, the contrast control characteristic that minimum, nominal and maximum user control setting is shown.Note that about the contrast control characteristic in case control voltage when reaching the lowest gain value of contrast part 5, even contrast control voltage continues to reduce, picture contrast does not further reduce yet.6 illustrate the brilliance control characteristic that nominal and maximum user set among the figure, unless because user's brightness settings is to be in or during greater than nominal user brightness settings, otherwise the restriction of brightness electronic beam current does not take place.
Fig. 2-5 points out that the resistor BR2 of change brightness DAC 15 and the value of BR3 are to the influence of brilliance control characteristic.Resistor BR2 has determined the begin relevant point of brightness beam restriction with user's contrast control setting with the ratio of BR3.Fig. 2 (RB2=270K BR3=0) points out, until contrast electronic beam current restriction equal or during near maximum till, the restriction of brightness electronic beam current can not take place.(BR2=0 RB3=270K) points out Fig. 5, and the brightness electronic beam current is limited in when having identical electronic beam current level with the restriction of contrast electronic beam current basically and begins.As Fig. 3 and 4 pointed, the middle scale of resistor R B2 and RB3 value causes that the starting point of brightness electron beam ductility limit changes between all points shown in Fig. 2 and 5.The characteristic that the value that changes resistor R B2 and RB3 can the appreciable impact contrast not be controlled.Set the starting point that influences the restriction of brightness electronic beam current though also note that the control of user's contrast, user's brilliance control is set does not influence the contrast control characteristic.
Fig. 2-5 goes back with dashed lines and points out, changes the influence of reference voltage VREF to the brilliance control characteristic.The size of reference voltage VREF has determined the control voltage of minimum brightness electronic beam current restriction together with the value of resistor R B3, RB4, RB5.Yet, should please note, till when the control voltage that the control voltage range has used up and the contrast electronic beam current limits of whole contrast electronic beam current restriction is its minimum value, brightness electronic beam current control voltage is not reduced under the nominal brilliance control voltage.Reducing of this brightness is stringent effort, with the irregular working situation of illustrative examples as lacking of proper care owing to picture tube 3 screen voltages.
Note that if reference voltage VREF changes, and need keep same electronic beam current threshold limit the time, then be necessary to change the value of resistor R S.Because the value of resistor R S is one of factor of decision electronic beam current restriction loop gain, if resistance value has changed, and need keep identical loop gain the time, the then also essential change of the value of resistor R G.
As one of ordinary skill in understanding, can be undertaken by specific needs the modification of preferred embodiment.For example, electronic beam current limiter means among Fig. 6 is a configuration similar in appearance to Fig. 1 device, but the numerical value of element changes, to be fit to (for example having the higher electronic beam current threshold limit of need, 2050 micromicroamperes) with different brilliance control voltage ranges (for example, the television system of the high average electronic beam current of 5.2V ± 0.7V).Between the emitter of transistor Q3 and the Rendezvous Point of resistor R B2 and RB3 (node 3), add protection diode CRP, to prevent the reverse breakdown of transistor Q3.
The electronic beam current limiter means also is different from the electronic beam current restraint device of Fig. 1 among Fig. 6 in others.Especially, increased auto contrast unit 23.Auto contrast's control unit 23 carries out signal peak (White-going peak of a singnal) in response to the corresponding white that shows luminance component image again, surpassed and given when deciding threshold value if white is carried out peak value, just reduced the contrast control voltage on the filtering capacitor CC.As shown in Figure 6, auto contrast's control unit 23 in response to the composite signal that is coupled to R, G on the picture tube 3, B signal (for example, and signal), this auto contrast's control device has been described in more detail in United States Patent (USP) 4,980,756, name is called " control-signals generator of television system (Control Signal Generator For Television Syste-m "), this patent is issued applicant W.A.Lagoni in the 1990.12.25 song.Auto contrast's control unit 23 is also in response to user's contrast settings, so that abolish automatic white peak restriction operation during in its maximum in user's contrast settings.Latter explanation, the user is more interesting in the image that obtains tool peak-peak-white portion rather than prevent defocusing of luminous point.For removing automatic white peak restriction operation, automatic control unit 23 comprises auxiliary low pass filter (not shown) and that sensing user contrast control sets and be used for conversion configurations (also not shown) the output of auto contrast's control unit 23 and filtering capacitor CC decoupling zero when the setting of user's compared with control is in its maximum level.This configuration has been described in more detail in u.s. patent application serial number 751,810, name be called " comprise the video signal system (Video Signal SystemIncluding Apparatus For Defeating an Automatic Control Arrang-ment) that stops to start automatic control inking device; by W.A.Lagoni and R.L.O ' Brien in 1991; 8,30 file an application.Remove the auxiliary low pass filter of part for the auto contrast who holds automatic contrast unit 23, the emitter follower that comprises NPN transistor Q4 and emitter load resistance RC4 is added on the contrast DAC 13, the position the Rendezvous Point of resistor R C1 and RC2 and comprise resistor R C3 and the low pass filter of filtering capacitor CC between.
Though the present invention directly views and admires television system with reference to showing on the screen that image directly is shown in single picture tube again, so it also can be in order to each electronic beam current red, green, blue picture tube of control projection television system.For example the device of Fig. 6 only promptly can be used for the projection television system of requirement 1650 micromicroampere electronic beam current threshold limits from 11.1 kilohms to 13.7 kilohms by the value that changes resistor R S.
Obviously, for those skilled in the art, also has other modification.These and other modification all is in the scope of the present invention that following claim scope is defined.
Claims (11)
1, a kind of electronic beam current restraint device of television system, described television system comprises picture tube (3) and vision signal is handled channel (1), has picture contrast part (5) and brightness part (7), give described picture tube with the vision signal (R, G, B) that processing is provided, and the user responds contrast control unit (13) and brightness control unit (15), to produce each user's contrast and brightness control signal, described electronic beam current restraint device comprises:
The device (17) of the electronic beam current that sensing is drawn by described picture tube;
Produce contrast electronic beam current control signal, to reduce the device (19) of picture contrast during above first threshold when the electronic beam current of sensing;
It is characterized in that, be coupled to described user and respond brightness control unit, with the device (RB4 that the level of described user's contrast control signal and nominal user brilliance control level corresponding to the nominal image intensity level are compared; RB5); And
Be coupled to described comparison means, with when the electronic beam current of (1) sensing surpasses second threshold value, (2) if when user's brilliance control level surpasses nominal user brilliance control level, produce brightness electronic beam current control signal to reduce the device (Q3 of image brightness; RB2, RB3).
According to the electronic beam current restraint device of claim 1, it is characterized in that 2, described brightness electronic beam current control signal generator means only reduces the brightness of image when contrast control signal reaches its minimum.
According to the electronic beam current restraint device of claim 1, it is characterized in that 3, described brightness electronic beam current control signal generator means only only reduces the brightness of image till image brightness is during at least near its nominal level.
According to the electronic beam current restraint device of claim 1, it is characterized in that 4, described brightness electronic beam current control signal generator means is in response to described contrast electronic beam current control signal.
According to the electronic beam current restraint device of claim 4, it is characterized in that 5, described first threshold is fixed.
6, according to the electronic beam current restraint device of claim 1, it is characterized in that, described user responds the pulse signal source (SWB) that brightness control unit comprises coding, reaches the described pulse signal of a filtering, responds the filter (CB) of controlling voltage to produce the user;
Described comparison means comprises: first (RB2) and second (RB3) resistive element, be coupled in series with between described pulse signal source and the voltage source (SWB), also comprise in response to the electronic beam current of sensing and be coupled in the threshode devices (Q3) of macerating the collection point of described first and second resistive element corresponding to the nominal image intensity level.
7, according to the electronic beam current restraint device of claim 6, it is characterized in that, described contrast electronic beam current control signal generating means (CRD, 19) comprise a transistor (Q2), first and second electrodes of this transistor (Q2) have defined a conductive channel, also have a control electrode to control the conducting of this pathway;
Described electronic beam current sensing is established device (17) and is coupled to described transistorized first electrode; Reference voltage (VREF) source (21) corresponding to described first threshold is coupled to described transistorized described control electrode; And
The described threshold device (Q3) of described comparison means is coupled to described transistorized second electrode.
According to the electronic beam current restraint device of claim 7, it is characterized in that 8, described reference voltage is also corresponding to the nominal image intensity level.
9, a kind of television system comprises:
Picture tube;
Vision signal is handled channel, comprises picture contrast and brightness part, so that the vision signal of processing to be provided to picture tube;
The user responds the contrast control unit, controls the contrast part that described vision signal is handled channel according to the setting of user's contrast;
The user responds brightness control unit, controls the brightness part that described vision signal is handled channel according to the setting of user's brightness;
Sensing apparatus, the electronic beam current of being drawn by picture tube with sensing; And
Be coupled to the electronic beam current restraint device of described sensing apparatus and described contrast and brightness control unit, when surpassing first threshold, the electronic beam current of sensing reduces the contrast of image, and when the electronic beam current of (1) sensing surpasses second threshold value and (2) if during greater than nominal (middle scope) image brightness level, reduce the brightness of image corresponding to user's brightness settings of image brightness level.
10, according to the television system of claim 9, be characterised in that,
Described first and second threshold value equates.
11, according to the television system of claim 9, be characterised in that,
Described electronic beam current restraint device only reduces the brightness of image till image brightness is during at least near middle range brightness level.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US807,468 | 1977-06-17 | ||
| US07/807,468 US5200829A (en) | 1991-12-16 | 1991-12-16 | Contrast beam current limiting arrangement with secondary brightness beam current limiting provisions |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1074322A true CN1074322A (en) | 1993-07-14 |
| CN1050955C CN1050955C (en) | 2000-03-29 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN92114696A Expired - Fee Related CN1050955C (en) | 1991-12-16 | 1992-12-15 | Contrast beam current limiting arrangement with secondary brightness beam current limiting provisions |
Country Status (12)
| Country | Link |
|---|---|
| US (1) | US5200829A (en) |
| EP (1) | EP0547456B1 (en) |
| JP (1) | JP3052225B2 (en) |
| KR (1) | KR960009798B1 (en) |
| CN (1) | CN1050955C (en) |
| CA (1) | CA2082243C (en) |
| DE (1) | DE69219867T2 (en) |
| ES (1) | ES2101009T3 (en) |
| MX (1) | MX9207294A (en) |
| MY (1) | MY108456A (en) |
| SG (1) | SG71654A1 (en) |
| TW (1) | TW216477B (en) |
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| US4253110A (en) * | 1979-12-14 | 1981-02-24 | Rca Corporation | Automatic kinescope beam current limiter with sequential control modes |
| JPS6043981A (en) * | 1983-08-22 | 1985-03-08 | Sony Corp | Beam current limiting circuit |
| US4599643A (en) * | 1983-12-29 | 1986-07-08 | Rca Corporation | Apparatus responsive to plural color video signals for amplitude limiting the video signals to assist beam current limiting |
| US4633320A (en) * | 1984-03-08 | 1986-12-30 | Rca Corporation | Video signal processor with automatic kinescope beam current limiter |
| US4689668A (en) * | 1986-07-14 | 1987-08-25 | Rca Corporation | Auxiliary kinescope beam current limiter with plural cascaded low pass filter and peak detector stages |
| JPS63121366A (en) * | 1986-11-10 | 1988-05-25 | Sony Corp | Television receiver |
| JPH0236673A (en) * | 1988-07-27 | 1990-02-06 | Hitachi Denshi Ltd | Method and apparatus for processing signal |
| US5134490A (en) * | 1989-04-18 | 1992-07-28 | Thomson Consumer Electronics, Inc. | Beam current limiter with brightness control threshold extension |
| US4980756A (en) * | 1989-08-25 | 1990-12-25 | Rca Licensing Corporation | Control signal generator for a television system |
| US4982287A (en) * | 1989-11-01 | 1991-01-01 | Rca Licensing Corporation | Control of brightness level adapted to control of contrast |
-
1991
- 1991-12-16 US US07/807,468 patent/US5200829A/en not_active Expired - Lifetime
-
1992
- 1992-04-28 TW TW081103327A patent/TW216477B/zh active
- 1992-11-05 CA CA002082243A patent/CA2082243C/en not_active Expired - Fee Related
- 1992-11-16 MY MYPI92002089A patent/MY108456A/en unknown
- 1992-12-05 ES ES92120791T patent/ES2101009T3/en not_active Expired - Lifetime
- 1992-12-05 DE DE69219867T patent/DE69219867T2/en not_active Expired - Fee Related
- 1992-12-05 SG SG1996002452A patent/SG71654A1/en unknown
- 1992-12-05 EP EP92120791A patent/EP0547456B1/en not_active Expired - Lifetime
- 1992-12-14 KR KR92024150A patent/KR960009798B1/en not_active IP Right Cessation
- 1992-12-15 JP JP4361654A patent/JP3052225B2/en not_active Expired - Fee Related
- 1992-12-15 CN CN92114696A patent/CN1050955C/en not_active Expired - Fee Related
- 1992-12-15 MX MX9207294A patent/MX9207294A/en not_active IP Right Cessation
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1087890C (en) * | 1994-08-29 | 2002-07-17 | 松下电器产业株式会社 | ABL control circuit, ACL control circuit, luminance/color difference signal processor and video display apparatus |
| CN102567959A (en) * | 2010-12-31 | 2012-07-11 | 新奥特（北京）视频技术有限公司 | Multi-way image grey adjusting method |
| CN102567959B (en) * | 2010-12-31 | 2016-10-19 | 新奥特（北京）视频技术有限公司 | A kind of multimode gradation of image method of adjustment |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0547456B1 (en) | 1997-05-21 |
| CA2082243A1 (en) | 1993-06-17 |
| CA2082243C (en) | 1999-08-03 |
| TW216477B (en) | 1993-11-21 |
| DE69219867D1 (en) | 1997-06-26 |
| MY108456A (en) | 1996-09-30 |
| EP0547456A2 (en) | 1993-06-23 |
| JPH05308593A (en) | 1993-11-19 |
| JP3052225B2 (en) | 2000-06-12 |
| KR930015653A (en) | 1993-07-24 |
| CN1050955C (en) | 2000-03-29 |
| EP0547456A3 (en) | 1993-10-20 |
| ES2101009T3 (en) | 1997-07-01 |
| US5200829A (en) | 1993-04-06 |
| DE69219867T2 (en) | 1997-09-11 |
| SG71654A1 (en) | 2000-04-18 |
| KR960009798B1 (en) | 1996-07-24 |
| MX9207294A (en) | 1993-07-01 |
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Legal Events
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| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C06 | Publication | ||
| PB01 | Publication | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C15 | Extension of patent right duration from 15 to 20 years for appl. with date before 31.12.1992 and still valid on 11.12.2001 (patent law change 1993) | ||
| OR01 | Other related matters | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20000329 Termination date: 20100115 |